FunScript for sure is not perfect and have many rough edges - getting started as new user is hard, getting started with different type of project even as experienced user is not perfect (for example Atom plugin requires completely different approach than normal web application), it has problems with "OO" features of JS so using it with frameworks which requires such approach is bit hacky, generated code is not perfect.

But i still like it and managed to create fancy stuff with it - Ionide, React.js + Material UI applications etc. Wouldn't recommend using it on production ( unless You want to commit really hard into FunScript project and probably fix lot of this stuff) - WebSharper is providing more complete, richer solution and commercial support if needed